Farnsworth D-15 Test

The Farnsworth D-15 test is a clinical assessment used to evaluate color perception by asking a person to arrange 15 colored caps in order of hue. The pattern of errors reveals the type and severity of color vision deficiency, distinguishing between protan (red), deutan (green), and tritan (blue-yellow) defects. In accessibility, understanding the type of color vision deficiency a user has helps inform design decisions about color palettes, contrast requirements, and the need for non-color-based information cues in digital interfaces.